Hi - just laying out my DWV lines for a powder room reno and want to make sure the toilet venting is done right. I have the lav to the right of the toilet (facing them head on) and the stack is to left of the toilet.

My plan was to have the lav drain run down and join a 3" line (sloping to the main stack) via a Wye. Next down the 3" would be the toilet coming down a 90 bend and then entering the 3" line via another Wye.

I believe it'll be okay to vent the lav by running a line up (and out the roof) where the drain enters the wall. Is that correct?

How/Where would I vent the toilet? I believe the toilet must be the last fixture in the run for this kind of setup - correct?